Hi, I have arround two days trying the beta bios and appears to be running stable. I used a 1 to 3 hub adapter from Parallel Miner (https://www.parallelminer.com/product/usb-3-0-pcie-riser-card-expansion) on pcie 6 (the last one on the motherboard) with two r9 380 connected. In the pcie5 I have connected a nvidia gtx 1060. When I connected the nvidia combined with a r9 380 on the hub I had problems but I'm not sure if it was because I used two different card types on the hub adapter (it should not be a problem) or because a failing riser I found on the go it was causing trouble.

Don't forget to enable 4g decoding option. I also disabled the motherboard gpu and its hd audio device on the bios.

I'm going to continue testing it and will update this post if needed.